A glance at the spec sheet of the new Walkman had us all a quiver. Here was a 16GB player cheaper than the equivalent iPod Nano and yet, on paper at least, better in almost every way. What's happened to the overpriced Sony of old?

Goodness knows, but we're pleased it’s changed its ways. The NWZ-S639F is the best MP3 player available anywhere near its price.

Inauspicious start

Whoa, slow down there; first impressions aren't quite so positive. Pleasing as the NWZ-S639F's aluminium front-and-backed form is and despite being the thinnest ever Walkman, it's not quite as thin as the Nano, and its by-the-numbers design stops far short of 'style icon'.

Also, the NWZ-S639's mobile phone-esque operating system is dull compared with Apple's all-singing, all-dancing ‘Cover Flow’.  

Its bundled software, Sony Media Manager, is similarly uninspiring, though fortunately the player is Windows Media Player  and drag-and-drop compatible, so it’s dead easy to fill with tracks from your library.

Drab but simple interface

Round the front is a 5-way keypad, 'Back' and 'Option' keys, while a volume rocker and hold switch sit on the right-hand side.

It's designed for one-handed operation and, old fashioned as it might seem, it's nice to get a 'click' after the gimmicky 'will it, won't it?' of lesser touch-sensitive machines.

But on to the really good stuff. As we've come to expect from Sony's players, the NWZ-S639F sounds fantastic.

Stick in a pair of good reference headphones and it swiftly proves itself to be the rival of almost any other player on the market with a detailed, dynamic and perfectly timed delivery. Everything is on show, so it won't suit poor-quality tracks, but it lends a welcome drive and openness to any recordings you play.

Spectacular sonics

Even the sound enhancement settings are decent. Avoid the 'surround' modes, which are like plunging your head underwater, but by all means try out 'Clear Stereo' and 'DSEE'. We preferred to have the latter disabled because of the treble splashiness it introduces but it's worth seeing if it suits your tastes.

The included headphones are great too, especially compared with the ones you'll get with an iPod. The semi-sound-isolating design offers rich, deep bass and smooth treble and midrange.

A headline feature that Sony Ericsson users will be familiar with is SensMe. It categorizes your music by pitch and tone, allowing you to quickly select tracks that match your mood.

It works moderately well, occasionally miscategorizing tracks (we got The White Stripes in 'Electronic') but generally doing what it should and proving a useful feature. And it needs to be, considering there's no on-the-go playlist function.

Star of the small screen

Video is similarly impressive. The screen's a dead ringer for the new Nano's but without the curved glass covering, making it better for use with overhead lighting. It lacks movement sensors so you need to manually change orientation (if you want to), but the video is crisp and smooth, and perfect for the odd clip.

While it's far from feature rich – Creative's Zen X-Fi, Sandisk's Sansa players and the iPod Touch put it to shame – the NWZ-S639F does have a very decent FM radio. It holds a signal well and sounds excellent.

The icing on the cake is its battery life. At 40 hours, it's 16 hours longer than the Nano's.

Put simply, if the NWZ-S639F were stuffed into the Nano's sculptured shell, it would be pretty much as good as MP3 players can get in 2008.

Stuff says... 

Sony NWZ-S639F review

Sony's on to a winner with the NWZ-S639F. It's the best compact MP3 player you can buy